Double Dragon 3: The Rosetta Stone (ダブルドラゴン3 ザ・ロゼッタストーン Daburu Doragon 3: Za Rozetta Sutōn?) is a side-scrolling beat 'em up produced by Technōs Japan that was originally released as a coin-operated arcade game in 1990. It is the second sequel to Double Dragon for the arcades, following Double Dragon II: The Revenge. A Nintendo Entertainment System game loosely based on the arcade version was released, along with conversions for the Sega Mega Drive/Genesis, Game Boy, and various computer platforms.
The premise of Double Dragon 3 is explained on the game's attract sequence: while returning to their home from a training trip, Billy and Jimmy Lee cross paths with a fortune teller named Hiruko. The fortune teller cryptically tells the brothers that they must collect the three "Rosetta Stones" scattered around the world in order to face a mysterious new adversary awaiting them in Egypt. Depending on the game's configuration, up to two or three players can play the game (similar to The Combatribes, another beat-'em-up by Technōs released during the same year). As usual, the first two players take control of Billy and Jimmy in that order, while the third player assumes the role of Sonny, a yellow-clad palette swap of the Lee brothers.
The game uses a three-button control configuration like the previous titles, but discards the directional-based attack buttons from Double Dragon II, reverting to the "Punch" and "Kick" setup of the first game. Most of the techniques from the first two titles are not featured in this installment such as the elbow punch and the hair pull, although new ones were added in their place such as a belly-to-back throw and a running head-butt. There are also techniques that can be performed with another player character such as a back-to-back hurricane kick and a triangle jump kick. The player can also jump over fallen enemies.
Certain areas in the game feature weapon shops where the player can gain additional power-ups for their character such as new moves, agility, energy, and weapons, by inserting additional credits into the game. The player can also purchase new playable characters that will replace their current character when they're killed. There are at least three additional character types in addition to the default one that the player starts the game with: the Urquidez brothers, the Chin brothers, and the Oyama brothers.
The game is divided into five stages, each taking place in a different country: America, China, Japan, Italy, and Egypt. Each stage feature their own enemy characters that fit with the setting and motif (i.e.: the enemies in Japan are swordsmen in a castle, with a ninja as the boss).
The Game Boy version (developed by Sales Curve) was released on August 1992, while the Mega Drive/Genesis port (developed by Software Creations) was released on December 1992.